The ERTU Proof of Performance Test of the CFA in 1995

Here we have a broadcaster ERTU operated under the Egyptian government. The engineering sector of the ERTU started developing their version of the CFA in 1989. First test from the roof of the Tanta station started in 1990 with only Barrel and disc at that time. Originally the station on 1161khz used a quarter-wave mast and this mast was kept as a standby unit and a reference for the first five years.

At that early stage Mr.Mahmoud Khattab then Head of Projects at the ERTU wrote this in the Electronics World + Wireless World of July 1992:

Egyptian CFA update
Following MC Hately, FM Kabbary and BG Stewarts crossed field antenna
(CFA) article "CFA: Working Assumption?"(EW + WW December 1990) I
would like to inform your readers of our progress with useing the CFA.
Experiments have continued since December 1990 and our CFA has been
developed to withstand 60kW RF power at medium frequency (a success
presented at the IEE Icap Conference in April 1991).
Further developments in structure, phasing unit and matching unit
have all been carried out, satisfying the need for 250 ohm matching
the transmitter and 37 ohms matching the CFA. Equal power sharing
of 30kW through each feeder to E and D plates of the CFA has been
achieved, obtained at in-circuit pure real resistance measured
directly at the input of each E and D plate.
Progress has also continued on evaluation of coupling and equivalent
circuit impedance – adding more proof to the CFA theory.
Our 60kW CFA is now being used successfully to transmit a regional
radio service to the Middle Nile Delta and serves a population of 15
million within a 50km radius around Tanta City. The CFA has delivered
a much wider bandwidth than a 0.25 wavelength mast radiator, with
equal or better field strength (63dB at 90km distance).
Application to long-wave broadcast at high power up to 250kW is now
under way to create a new LW transmission for upper Egypt.
We believe our work is part of the new age of antennas which will
lead to a major change in configuration of broadcast transmitting
centres, especially in the medium and long wave range.
Mahmoud Khattab
Egyptian Radio and Television Union Cairo

Around 1994–95 the CFA was developed with the first step of three with
a top cone. The ERTU was then satisfied with its performance and scrapped the old quarter-wave mast. A comparison test between the two antennas was published in this paper:

Extremely Small High Power MW Broadcasting Antennas
FM Kabbary M Khattab MC Hately
Proceedings of the 1997 IEE International Broadcasting Convention
(IEE Conference Publication No.447); pp. 421 – 426.

It was written by Mahmoud Khattab (now the Chairman of the Broadcast Engineering Sector of the ERTU) together with the patent holders.

The values are seen to be averaging some 3dB better then the quarter wave vertical over the whole service area.

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Egyptian Radio and Television Union (ERTU)
1995 Comparison Test CFA against Quarter-Wave Mast
Tanta Radio Station in the Nile Delta
Performed during February 1995
Time of Measurements: 10am to 2pm
Frequency: 1161 kHz
Transmitter Power: 30 kW
Modulation: 100%
Measured Field Strength in dBuV/m
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ITU 1/4 Mast || CFA 6m – Tower 65m || Distance/Direction/Location
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078 dBuV/m || 076 – 069 = +7dBuV/m || 075km 158° Shoubra
074 dBuV/m || 077 – 076 = +1dBuV/m || 095km 048° Damietta
073 dBuV/m || 072 – 069 = +3dBuV/m || 100km 293° Alexandria
083 dBuV/m || 085 – 083 = +2dBuV/m || 052km 290° Damanhur
087 dBuV/m || 089 – 086 = +3dBuV/m || 042km 059° El Mansoura
085 dBuV/m || 089 – 086 = +3dBuV/m || 047km 150° Dosouk
088 dBuV/m || 084 – 081 = +3dBuV/m || 038km 151° Benha
110 dBuV/m || 105 – 102 = +3dBuV/m || 005km 195° Tanta
086 dBuV/m || 083 – 082 = +1dBuV/m || 046km 157° Toukh
091 dBuV/m || 094 – 088 = +6dBuV/m || 032km 359° Fafr el Sheik
097 dBuV/m || 098 – 089 = +9dBuV/m || 018km 284° Kafr el Zaiat
077 dBuV/m || 065 – 059 = +6dBuV/m || 080km 162° Cairo
069 dBuV/m || 073 – 069 = +4dBuV/m || 123km 064° Port Said
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First Column is the expected Field Strength according to the FS-Curves of Rec.ITU-R P.368–7 for a Quarter Wave Mast over a 30 mS/m ground concuctivity as of the Nile Delta.